of psychological function. Jung proposed the existence of two dichotomous pairs of cognitive functions: The "rational" (judging) functions: thinking and feeling The "irrational" (perceiving) functions: sensation and intuition Jung went on to suggest that these functions are expressed in either an introverted or extraverted form. According to Jung, the psyche is an apparatus for adaptation and orientation, and consists of a number of different psychic functions. Among these he distinguishes four basic functions: sensation—perception by means of immediate apprehension of the visible relationship between subject and object intuition—perception of processes in the background; e.g. unconscious drives and/or motivations of other people thinking—function of intellectual cognition; the forming of logical conclusions feeling—function of subjective estimation, value oriented thinking Thinking and feeling functions are rational, while sensation and intuition are nonrational. According to Jung, rationality consists of figurative thoughts, feelings or actions with reason — a point of view based on a set of criteria and standards. Nonrationality is not based in reason. Jung notes that elementary facts are also nonrational, not because they are illogical but because, as thoughts, they are not judgments. Attitudes: extraversion and introversion Analytical psychology distinguishes several psychological types or temperaments. Extravert (Jung's spelling, although some dictionaries prefer the variant extrovert) Introvert Extraversion means "outward-turning" and introversion means "inward-turning". These specific definitions vary somewhat from the popular usage of the words. The preferences for extraversion and introversion are often called attitudes. Each of the cognitive functions can operate in the external world of behavior, action, people, and things (extraverted attitude) or the internal world of ideas and reflection (introverted attitude). People who prefer extraversion draw their energy toward objective, external data. They seek to experience and base their judgments on data from the outer world. Conversely, those who prefer introversion draw their energy toward subjective, internal data. They seek to experience and base their judgments on data from the inner world. The attitude type could be thought of as the flow of libido (psychic energy). The functions are modified by two main attitude types: extraversion and introversion. In any person, the degree of introversion or extraversion of one function can be quite different from that of another function. Four functions: sensation, intuition, thinking, feeling Jung identified two pairs of psychological functions: The two irrational (perception) functions, sensation and intuition The two rational (judgment) functions, thinking and feeling Sensation and intuition are irrational (perception) functions, meaning they gather